This invention relates to a fluid-conducting swivel and method for operating the same and, more particularly, but not by way of limitation, relates to such a swivel which is free of friction creating seals.
Fluid-conducting swivels are known and commercially available. Typical applications include fluid-driven rotating machinery and tools and fluid-spraying rotating cleaning equipment. Shortcomings of prior fluid-conducting swivels include the use of O-rings, packing, or other friction-generating seals which make surface contact to seal and prevent fluid passage between the relatively rotating members of the swivels. The friction created by such seals reduces the efficiency of the equipment and increases the required maintenance. The physical contact between such seals and the rotating member(s) generates the friction which retards the ability of the members to rotate and which causes the seal to deteriorate relatively rapidly.
U.S. Pat. No. 4,923,120 to Hammelmann discloses a nozzle device having a labyrinth-like sealing gap which requires close machining tolerances and appears to be relatively expensive to manufacture and assemble. Hammelmann also discloses using a vacuum created at the outlet of a pressurized orifice to draw fluid through the labyrinth-like sealing gap and improve its sealing action. This ingestion or inspiration through the gap increases the pressure lost in the nozzle device.
Therefore, there is a need for a fluid-conducting swivel and method of operating the same which does not require the use of friction-generating seals or relatively expensive labyrinth-type seals, which requires little if any pressure loss across the swivel, and which is relatively inexpensive to manufacture and maintain.